Linked Life Data

18296735

Source:http://linkedlifedata.com/resource/pubmed/id/18296735

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-2-25
pubmed:abstractText
Nkx3.1 is a member of the NK2 class of homeodomain proteins and is expressed in development, being an early marker of the sclerotome and prostate gland. It has been shown to be a critical factor for prostate differentiation and function. Previous studies suggested that Nkx3.1 interacts with Serum Response Factor (SRF) to transactivate the Smooth Muscle gamma-Actin (SMGA) promoter. In studies presented here, we examined the molecular mechanisms underlying the functional synergy of these factors upon SMGA transcription. We demonstrate that full length Nkx3.1 physically interacts with SRF in the absence of DNA and that these factors are able to co-associate in cellular context using a mammalian two-hybrid system. The segment of SRF responsible for Nkx3.1 interaction was mapped to a approximately 30 amino acid region (AAs 142-171) at the N-terminal segment of the MADS box. Two separate regions of Nkx3.1 were found to mediate interactions with SRF. Interestingly, recognized domains of NK2 proteins, namely the TN, homeodomain DNA binding segment, and the NK2-SD do not participate in SRF interactions. One of the Nkx3.1 SRF binding domains was mapped to the N-terminal of the protein consistent with recent studies of these proteins using NMR spectroscopy by Gelmann and colleagues (1). A second SRF binding region was mapped to amino acids C-terminal to the homeodomain. Structural predictions indicate that both of the SRF interacting segments are largely hydrophobic in character and beta-strand in structure. With co-transfection transcriptional analyses we found that interaction between SRF and Nkx3.1 as well as DNA binding by both factors was required for the observed transcriptional synergy. Thus our studies have identified novel protein-protein interacting domains within Nkx3.1 and SRF that operate in concert with their respective DNA binding domains to mediate functional transcriptional synergy of these factors to regulate SMGA gene activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1535-3702
pubmed:author
pubmed:issnType
Print
pubmed:volume
233
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-309
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Structural and functional analysis of domains mediating interaction between the bagpipe homologue, Nkx3.1 and serum response factor.
pubmed:affiliation
Department of Systems Biology and Translational Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural